A typical scintillator crystal package 100 is assembled from the individual parts shown in FIG. 1. A scintillator crystal 102 is wrapped or otherwise surrounded by one or more layers of a preferably diffuse reflective sheet that is preferably formed from a fluorocarbon polymer. The wrapped crystal 102 can be inserted in a hermetically sealed housing 104 which may already have the optical window 106 attached. The window 106 may be sapphire or glass, as noted in U.S. Pat. No. 4,360,733. The housing 104 may then be filled with a silicone (RTV) that fills the space 114 between the crystal 102 and the inside diameter of the housing 104. Optical contact between the scintillator crystal 102 and the window 106 of the housing 104 is established using an internal optical coupling pad 108 comprising a transparent silicone rubber disk.
Alternatively, the scintillator may be surrounded by a reflecting powder that is chemically and mechanically compatible with the scintillator material. Such powders could be Al2O3, TiO2, BaSO4 or similar materials. The powders can be packaged directly around the scintillator crystal 102 or be supported in a reflecting or transparent elastomer. With proper surface preparation, metallic reflectors such as Ag can be used as well, if they are chemically inert in the presence of the scintillator material.
An end cap is sealed over the open end to complete the scintillator package 100 and prevent exposure of the scintillator crystal 102 to air that would degrade performance. An internal spring 110 pushing against the scintillator 102 through a pressure plate 116 may be included to provide axial force on the scintillator crystal 102 to insure that optical contact is maintained. These general processes are known to those familiar with the art, as described in U.S. Pat. No. 4,764,677.